Action 14f13, also called Sonderbehandlung (special treatment) 14f13 and Aktion 14f13, was a campaign by Nazi Germany to murder Nazi concentration camp prisoners. Also called invalid or prisoner euthanasia, the sick, the elderly and those prisoners who were no longer deemed fit for work were separated from the rest of the prisoners during a selection process, after which they were murdered. The Nazi campaign was in operation from 1941 to 1944 and later covered other groups of concentration camp prisoners. Background In spring 1941, Reichsführer-SS Heinrich Himmler met with Reichsleiter Philipp Bouhler, head of the Hitler Chancellery to discuss his desire to relieve concentration camps of excess ballast, sick prisoners and those no longer able to work. Bouhler was Hitler's agent for implementation of Aktion T4, the euthanasia program for the mentally ill, disabled and inmates of hospitals and nursing homes deemed unworthy of inclusion in Nazi society. Himmler and Bouhler transferred technology and techniques used by Aktion T4 personnel to concentration camps and later to Einsatzgruppen and death camps, to efficiently murder unwanted prisoners and inconspicuously dispose of the bodies. Aktion T4 was officially terminated by Hitler on August 24, 1941 but it was continued by many of the physicians who had been involved, until Nazi Germany was defeated in 1945. Organization Bouhler instructed Oberdienstleiter Viktor Brack, the head of Hauptamt II (Main Office II) of the Hitler's Chancellery (Kanzlei des Führers) to implement the new order. Brack was already in charge of the various front operations of T4. The scheme operated under the Concentration Camps Inspector and the Reichsführer-SS under the name "Sonderbehandlung 14f13". The combination of numbers and letters was derived from the SS record-keeping system, 14 for the Concentration Camps Inspector, f for the German word deaths (Todesfälle) and 13 for the cause of death, in this case murder by poison gas in the T4 killing centers. "Sonderbehandlung" ("special action"literally "special handling") was the euphemistic term for execution or killing. Selections, first phase After the operation began in April 1941, a panel of doctors began visiting concentration camps to select sick and incapacitated prisoners for "elimination". This panel included those already experienced from Aktion T4, such as professors Werner Heyde and Hermann Paul Nitsche and doctors Friedrich Mennecke, Curt Schmalenbach, Horst Schumann, Otto Hebold, Rudolf Lonauer, Robert Müller, Theodor Steinmeyer, Gerhard Wischer, Viktor Ratka and Hans Bodo Gorgaß. To speed up the process, camp commandants made